The present invention relates to a stranding machine system with a single lay device and take up device for the rope. More particular-y, it relates to a device of this type in which a take up coil and a single layer rotor, which rotates and encompasses the take up coil, are disposed coaxially with respect to each other, the take up coil and the single layer rotor are movable axially in a reciprocating movement relative to each other for generating a laying stroke for the rope, and the rope is guided along the single lay rotor to the take up coil, whereby for the take up process a difference of the speed of the take up coil and the single lay rotor is generated depending from the given obtained taking up diameter of the take up coil.
In a known stranding machine system of this type (disclosed in DE-PS No. 20 37 607) the rope is premade in a so-called prestranding machine with a driven drawing off device Thereafter the rope is fed to the single lay device and take up device in such a manner that it is fed to a single lay rotor in front of the take up coil and along the same to the take up roller This take up roller is mounted in a free lying manner, is separately driven and is reciprocally moved in axial direction for laying the rope. Therefore, the take up coil immerses into and out of the known single lay rotor. When the operating speed is obtained after the smooth start of the system, the speed of the single lay rotor remains constant until the take up roller is full or until an eventual emergency breaking is required, generally over a longer period of production. In order to take up the rope with the known system, the take up coil must rotate coaxially with the single lay rotor at a high speed. However, as is known the take up coil must have a certain differential rotating speed in relationship to the single lay rotor. Since the rope is fed with a constant trajectory speed or feeding speed, the speed of the take up roller must be adjusted in dependence on the instantaneous winding diameter and thereby on the degree of filling of the coil, as is well known. At first, the differential rotating speed of the almost empty coil will be relatively high in relationship to the single lay rotor, but reduces during an increasing take up diameter.
In the known systems (for example, in accordance with DE-PS No. 20 37 607 or in other comparable single lay devices and take up devices) the control of the rotating and stroke speeds of the reciprocating take up coil is performed in dependence on the predetermined rotating speed of the associated single lay rotor, on the one hand, and with consideration of the associated feeding speed of the rope derived therefrom, on the other hand, for maintaining constant rope lay lengths or tolerable rope tensile stress. Thereby, the take up roller is actually secondarily fed with respect to the primarily controlled single layer rotor.
Such an adaptation of the take up rotating speed and the laying stroke speed can be realized without any difficulties from the point of view of the control technology, as long as the production is performed with a constant rope speed or must be only slightly accelerated or delayed. However, for particularly rapid stranding machine systems the known solution of the single layer device and the take up device results in practically insuperable difficulties, i.e., for the following reasons: An increase in the lay number simultaneously leads to a highest degree of stranding speed or rope feeding speed and thereby also to a corresponding rotating speed for the take up coil, which either leads or lags with a relative low speed difference with respect to the single lay rotor in the known solution. A severe increase of the rotating speed of the separately driven take up coil in the known system results in undesirable high demands and disadvantages. In particular when stranding thin or tensile sensitive stranding elements difficulties occur for the following reasons: When taking up a rope on a take up roller which rotates around its own axis, the control of the tensile stress of the rope to be taken up is necessarily always associated with a corresponding change of the rotating speed of the coil. A take up drive must be provided, on the one hand, and a brake which acts on the take up coil, on the other hand. Unforseeable and quickly applied emergency braking of the take up roller are critical by maintaining a constant tensile stress in ropes and in particular with tensile sensitive ropes, for example, thin but multiwired high-voltage stranded wire made from copper. The particular difficulty for a coordinated rapid braking of the single lay rotor and the take up coil is that the take up coil which lags behind the rotor has a completely variable mass and above all an increased degree of a variable mass inertia moment depending on the obtained degree of take up. The dynamic mass inertia is proportionally of the fourth power of the obtained take up diameter. The braking moment is directly proportional to the mass inertia moment and the braking time is reversely proportional to the braking moment, which means, that for maintaining of uniform braking times a braking equipment would be provided for the single lay rotor, on the one hand, and the lagging take up coil, on the other hand, which would have to be equipped with an extremely high set range for the unforseeable large breaking moment. Thereby this equipment must also be able, despite an excessive variation span, to completely brake within a few seconds accurately controlled by high speeds. Such a braking equipment would be realizeable in practice only with great efforts and would therefore not be feasable either technically, or economically. In the known systems such emergency brakings would result in damages to the rope or in loop forming, or the like. Therefore, the worst disadvantage of the known systems is seen, above all, in that the take up coil must perform the axial lay stroke movement with its relatively large and variable mass, on the one hand, and must be controlled, i.e., must be controlled in its given movement conditions in its rotating speed during the operation and in particular during the described brakings, on the other hand.